Two-speed turntable drive



Aug. 25, 1936. 'B. R. CARSON TWO-SPEED TURNTABLE DRIVE Filed Jan. :50,1951' IN VEN TOR R. Carso n,

HAS A T TORN This invention relates Patented Aug. 25, i936 Two-snaproan-roam niuva Wu B. Carson, collingawood,

lignor, b esne assignm y Amel-ica, New z k. N. 2., a corware notation ofnotation of Dela N. 1., as- -to Radio Gor- Application January. 30,1981, Serial No. 512,244

to turntable drives and more particularly, although not exclusively, toa variable speed drive for a phonograph turntable.

In reproducing sound from records of the disc ime. it is necessary torotate the record disc at a constant predetermined speed. It iscustomary, for example, to operate phonographs such as are used in thehome, at a speed of 78 or 80 R; P. M.

More recently, however, there have been introduced record tablets whichare operated at a much slower speed, as, for example, those used inconnection with synchronized sound' and motion picture work which areoperated at a speed of about 33.3 R. P. M.

It will, therefore, be obvious that a record tab- .iet intended forreproduction by one type of phonograph apparatus, cannot be properlyreproduced by another type of phonograph apparatus andv vice versa.Accordingly, my invention resides in the provision of an improved drivemechanism whereby record tablets operable-at diflerent constant angularspeeds may be reproduced at their proper tive manner.

It is, therefore, the primary object of my invention to provide a drivefor phonographs whereby diii'erent tively imparted to the turntable atwill.

Another object of my invention is to provide a phonograph wherein thespeed of the turntable may be changed at will from one constant speed toanother by the simple manipulation of a lever.

Still another object of my invention is to provide a-phonograph whichembodies speed change mechanism whereby the angular velocity of theturntable may be instantly changed from one speed to another at will.

Another object of my invention is to provide a phonograph which isadapted for the proper reproduction oi record tablets. which operate atdifferent constant angular speeds.

Still another object of my invention is to provide a phonograph having atwo-speed turntable drive whereby two difl'erent types of record discsspeed in a convenient .and eflecmay be reproduced at their properreproducing speed.

. vide a phonograph mechanism erated independently of or which may becom- Still another object of my invention is to prowhich may be opbinedwith a portable type of moving picture projector sound with motionpictures, as, for example, in

the home, and wherein theangular velocity of an phonograph turntable maybe 'table may be angular speeds may be selecadapted for thesynchronization of 18 Claims. (01. 214-9) changed at will for thereproduction of the usual type of record tablet or special recordtablets adapted for reproduction of sound in conjunction with motionpictures. p

More specifically stated, it is an object of my invention to provide aspeed change mechanism for phonographs whereby, under one operatincondition, as, for example, in the reproduction of standard phonographrecord discs, the turndriven through a direct coupling to a motive meansat a given speed, while under another operating condition, as, forexample, in the synchronization of special sound record discs withmoving picture projection apparatus, the turntable will be driven by thesame motive means but through an indirect coupling at another givenspeed, the change from one coupling to the other being instantaneouslyat will.

The novel features that I consider characteristic of my invention areset forth with particularity in the appended claims. The inventionitself, however, both as to its organization and its method ofoperation, together with additional ob- Jects and advantages thereof,will best be understood from the following description of a specificembodiment. when read in connection with the accompanying drawing, inwhich:

Fig. 1 is a fragmentary plan view of a phonographmechanism embodying myinvention, with the turntable removed:

Fig. 2 is a fragmentary view similar to Fig. 1, showing my inventionwith the parts thereof shown in another position;

Fig. 3 is a side elevation of a drive mechanism constructed inaccordance with my invention, as applied to a turntable and motortherefor with the motor board broken away and in section;

Fig. 4 is a vertical sectional view of Fig. 3; and

Fig. 5 is a fragmentary detail view of the control lever in anotherposition from that shown in Fig. 2.

Referring to the drawing, the apparatus shown comprises a constant speedmotor l0 embodying a suitable reduction gear drive (not shown) which issuspended in a well-known manner from the underside of a motor board uhaving a suitable means of a set screw II, said driving gear beingadapted to drive the turntable. I 6 which is rotatably mounted on thespindle ll, through a speed change driving unit B with which the drivinggear ll cooperates.

' The sp'eed change unit B comprises a substan-- tially annular clutchplate having a bearing .hub or boss l8 concentric therewith and attachedthereto in anyapproved manner. The bearing hub t8, together with theclutch plate ll, are provided with a central bore ii! for the receptionof a rotatable sleeve 20 having a ratchet flange 2| formed, at the upperend thereof, and a spur gear 22 staked or otherwise seemed to theopposite or lower end of; the sleeve 20. From an inspection of Fig. 4,it wilhbe apparent that the gear 22 rotates the sleeve 20 andincidentally prevents the longitudinal movement ofthe said sleeve in thebore i9.

Struck out from the plane of the clutch plate at a point adjacent theperiphery thereof, is an ear 23 so deformed that the major portionthereof is oflset from the underside of the plate l1 parallel therewith.Secured to and depending from the ear 23 in spaced relation to the axialcenter of the gear '22, isa stub shaft 24 adapted for rotatablyreceiving and retaining a bearing sleeve 25 having a pair ofconcentrically arranged gear 28 and 21 secured thereto so that thesleeve. 25 and the gears 26 and 21 will revolve "as a unit. The gear 26is of such size that it will freely mesh with the gear 22, while thegear2'! is adapted to mesh with and be driven by the driving gear It carriedby the spindle l3, when the speed change unit B is rotatabiy mounted onsaid spindle. Y

Means are provided for connecting and disconnecting the clutch plate H.in and from driving relation with the ratchet flange 2|. In theillustrated embodiment of my invention, this means is constituted by aclutch mechanism of the pawl and ratchet type and comprises a curvedpawl 28 which is pivoted at 29 to the upper surface of the clutch plateI1, said pawl 22 being provided with an inwardly projecting tooth 3|)which is adapted for engagement with a plurality of notches or recessesti-formed in and about the periphery of the ratchet flange 2| whichrotates with the sleeve 20 relative to the turntable spindle It at onespeed and with the spindle at another speed, above the clutch plate Hand in the plane of the tooth 30.

A sprint, 32 having one end thereof secured to an upstanding pin 33carried by one end of thepawl 28 and its opposite end to an upstandingpin 34 carried by the clutch plate Il, tends to maintain the tooth 30 inengagement with one of the recesses 3|, formed in the ratchet flange 2|,when the pawl 28 is in released position.

When the pawl 28 is so engaged with the ratchet flange 2|, the entirespeed change unit B rotates with the spindle It at its own speed whichin operation remains constant, since the gears 22, 26, and 21 are lockedagainst rotation about their own axes, but are carried about the axis ofthe spindle it. However, when the tooth 30 formed with the pawl 28, isout of engagement with the ratchet flange 2|, the clutch plate remainsstationary while the ratchet flange 2| continues to revolve but at amuch slower speed than the speed ofthe spindle l3 since the gears 22,26, and 21 are now'free axes in response to the driving gear M which isfixed to the spindle I3.

A lever 35 adapted for controlling the speed change unit 13, is pivotedintermediate its ends the clutch plate H, as

' i2 and the abutment 43 are ratchet flange 2|.

to rotate about their own nected to the lev r 35 as at 39 and its otherend anchored to an upstanding pin fill carried by the baseplate 31,functions to hold the lever 35 in either one of its two positions asclearly shown in Fig. 1.

The outer free end of the lever 35 is formed to provide a finger grip 6|while the opposite or inner end of the said lever is formed to provide ahook or toe 42 for engaging an abutment 43 formed on one end of the pawl28 by means of which the tooth 3|) formed on the said pawl is releasedinto or held out of engagement with the ratchet flange 2|.

From an examination of Figs. 2 and 5, it will be apparent that when thelever 35 is moved to the left as seen in Fig. 1, the hook or toe t2formed on the inner free end of the lever 35, will partially engage theabutment 43 formed on one end of the curved pawl 28 during its rotationwith shown in Fig. 5 and thereby withdraw the tooth 30 sumciently out ofengagement with the ratchet flange 2| to free it therefrom. At the sametime, it will also be apparent that the periphery of the'clutch plate I1is formed to provide a cam surface having a shoulder or step M. Fromthis it follows that further inward movement of the hook or toe 52toward the spindle is is not possible until the shoulder 44 has passedthe pin 35 carried by the lever 35, due to the rotation of the clutchplate l1 and the influence of the spring 38 on the lever 35. When thishas taken place, the toe 62 will be in full engagement with the abutment63 as clearly shown in Fig. l. 1

The function of the pin d5 when in the position shown in Fig. 1 is toprevent anti-clockwise movement of the clutch plate i! when the toe infull engagement out of contact with the The said anti-clockwise movementof the clutch plate i'l would ordinarily to hold the tooth 30 -bebrought about by the pull exerted by the spring 32 on the clutch platell when the pawl 28 is being held in the position shown in Fig. 1.

The preferred means for effecting a driving connection between theturntable i6 and the ratchet flange 2|, forms the subjectmatter of myco-pending application, Serial No. 487,115, filed October 8, 1930, forTurntable drive and, briefly stated, comprises a vertically disposed pin65 carried by the ratchet flange 2| and adapted to co-operate with ayieldable pin 41 vertically disposed in the hub or boss E8 formed on theunderside of. the turntable i6, and a friction washer 39 which is seatedin an annular recess formed in the upper surface of the ratchet flange2| for co-operation with the bottom face of the hub 68 forming a part ofthe turntable i5 to irictionally drive the same, the said pins 66 and Mbeing adapted under certain conditions to impart a positive drive to thesaid turntable.

The operation of the speed change turntable drive herein illustrated anddescribed is as follows:

Assuming that it is desired to operate a phonograph-embodying my presentinvention for the reproduction of record tablets" which operate at aconstant angular speed of 'I8'or R. P. M., such record tablets are placeupon the turntable It in the usual manner and the said turntablereleased for rotation or the rotation thereof otherwise brought about ina well-known manner.

point, should the control lever 35 be in .to the right of Fig. 1 torelease the pawl 26 as clearly shown in Fig. 2 for a turntable speed of78 R. P. M. before the sound-reproducing instrumentality is placed on arecord tablet of the type as above stated. I

With the control lever 35 now in a position opposite to that shown inFig 1, it will be readily apparent that the gears 22,26, and 21 are nowlocked against rotation about their axes with the result that the entir,speed change unit B will rotate with the spindle l3 at its normal speedthrough the agency of the driving gear ll.

, Conversely, if it is desired to operate a phone-.- graph embodying mypresent invention for the reproduction of record tablets whichoperate ata constant angular speed of 33.3 R. P. M., such record tablets areplaced upon the turntable I6 in theusual manner and the said turntablere:

leased for rotation or the rotation thereof otherwise brought about inawell-known manner.

At this point, should the control lever 35 be in the position shown inFig. 2, it must be moved to the left hand position as shown in Fig. 1 todisengage the tooth 36 carried by the pawl 28, tom any one 01' thenotches 3! formed in the ratchet flange 2| to efiect a turntable speedof 33.3 R. P. M., before the sound reproducing instrumentallty is placedon a record tablet of the type as above stated.

With the control lever 35 now in the position shown in Fig. 1, it willbe readily apparent that the gears 22, 26, and 21 are now free to rotateabout their own axes. Since the entire speed change unit B is now heldstationary, the driving gear M will drive the gear" which is secured tothe sleeve l8, through the gears 26 and 21 whereby the ratchet flange2lformed with the sleeve l6, will rotate at a speed which'is below thatof the spindle or relatively thereto due to the ratio of the said gears.

The final drive coupling between the ratchet flange 2| and the turntablel6 forms the subject matter ofmy copending application as hereinidentified.

Although I have shown and described certain specific embodiments of myinvention, I am fully aware that many modifications thereof arepossible. My invention, therefore, is not to be restricted exceptinsofar as'is necessitated by the prior art and by the spirit of theappended claims.

I claim as my invention:

1. In a phonograph, the combination of a motor driven spindle operableat a constant predetermined speed, speed change mechanism comprising agear train rotatably mounted on said spindle as a unit and including aclutch, a record support rotatably mounted on said spindle and adaptedto be driven by said mechanism, means carried by said spindle fordriving said gear train at one speed and said speed change mechanism asa unit at another speed and means for selectively controlling saidclutch, whereby either one of said speeds may be transmitted to saidsupport through said mechanism.

is disengaged and at the 2. In a phonograph, the combination of aspindle operable at a constant speed, a turntable rotatably mounted onsaid spindle, a speed change mechanism mounted as a unit on said spindleand including apawl and ratchet clutch, said unitbeing adapted todrivesaid tumtable at a speed below that of said spindle when saidclutch when said clutch is in engaged position, and

speed of said spindle,

manually operable means for eng ng and disengaging said clutch at will.

3. In combination, a spindle operable at a constant speed, a speedchange mechanism mounted on said spindle as a unit and including a pawland ratchet clutch, means carried by said spindle for driving themechanism of said unit, a record sup port rotatably mounted on saidspindle and adapted to be driven by said unit, and manually operablemeans for controlling said clutch whereby said record support is drivenby said unit at one or the other of two different speeds.

4. In a phonograph, the combination of a motor including a spindleoperable at a constant speed, a record support mounted'on said spindle,a speed change gear mechanism mounted on said spindle as a unit betweensaid motor and record support and including a clutch, drive meansconnecting said mechanism and spindle, means carried by said mechanismfor engaging and driving said record support, and means external to saidrecord support for controlling said clutch to effeet a charge in thenormal speed of said record support.

5. In a phonograph, the combination of a motor including a spindleoperable at a constant speed, a. record support revolubly mounted onsaid-spindle, a-reduction gear mechanism revolubly mounted onsaidspindle as a unit between said motor and record support and including aclutch, drive means connecting said mechanism and spindle, means carriedby said mechanism for engaging and driving said record support, andmeans external to said record support for controlling said clutch toeffect a change in the normal speed of said record support.

6. In a phonograph, the combination of a motor including a spindleoperable at a constant speed. a record support loosely mounted on saidspindle, a speed changing unit loosely mounted on said spindle betweensaid motor and record support and including a clutch, power transfermeans carried by said spindle adapted to cooperate with said unit, meanscarried by said unit for engaging and driving said record support, andmeans external to said record support for controlling said clutch toefiect a change in the normal speed of said record support.

7. In a phonograph, the combination of a motor including a spindleoperable at a constant speed, a gear train revolubly mounted on saidspindle as a unit and including a clutch, drive means connecting saidgear train and spindle, a record support revolubly mounted on saidspindle and adapted to be driven by said unit, and manually operablemeans adapted to control said clutch whereby said record support isdriven through said gear train at a speed diil'ering from that of saidspindle. Y

8. In a phonograph, the combination of a motor including a spindleoperable at a constant speed, a record support loosely mounted on saidspindle, a reduction gear mechanism loosely mounted on said spindle as aunit between said motor and record support and including a pawl andratchet clutch, spindle adapted to ternal to said record Support forcontrolling said clutch to eii'ect a change in the speed of said recordsupport.

. 9. In combination, a spindle operable at a constant speed,-a speedchange mechanism rotatably mounted on said sp die as a unit andincluding a pawl and ratchet clutch, means carried by said spindle fordriving said mechanism, a record support rotatably adapted to be drivenby said unit, means manually operable at will for controlling saidclutch whereby said record support is driven' by said unit-at one or theother of two fixed speeds, and oo-operative means carried by saidlast-named means and said unit for preventing movem'en of said unit atone of said two speeds.

10. In a phonograph, the combination of a mo- -tor driven spindleoperable at a constant speed,

a turntable loosely mounted on said spindle, a two speeddriving-mechanism mounted on said spindle as a unit and including a pawland ratchet clutch, drive means coupling said mecha-.

nisrn to said spindle, means carried by said -mechanism adapted toengage and drive said turntable, manually operable j so . from the fastdrive of the turntable.

of the latter, a speed reducing transmission between the shaft and theturntable,'--and means for placing said transmission at will into or outof operative connection. v

l2. In a phonograph of the type comprising a driving motor constructedfor speed thereof within a narrow range, a turntable shaft driven 7motor, a turntable-thereon, and a speed reducing transmission betweenthe shaft and the turntable, and means for short circuiting the speedreducing transmission at will for 13. A phonograph for use conventionalphonograph records and for modern slow-speed records, said phonographsincluding a conventional shaft, a direct connection, and a connection offixed speed reducing ratio between the shaft and the turntable andmanually controlled means for selectively throwing said direct or saidspeed reducing connection into operation respectively for fast speed ofthe turntable and'for slow speed thereof.

14. A phonograph of the type including a motorboard, a driving motorthereunder, a spindle mounted on said spindle andv alternatively formotor and a turntable openers driven therefrom and protrudingthereabove, a turntable on said spindle adapted toflbe driven directlytherefrom at the rotary speed thereof, and an' alternative drive betweenthe spindle andsaid turntable having a fixed s changing ratio effectiveto cause driving of the turntable at a rotary speed having a definiteratio with respect to that of the spindle.

15. The combination with a phonograph turntable adapted to rotaterecords of different re producing speeds, of a motor for driving saidturntable, a directdrive between said motor and turntable, adiflerential drive therebetween, and means for selectively driving saidturntable through either one of said drives.

16. The combination with a phonograph turntable adapted to rotaterecords of diiferent reproducing speeds, of a motor for driving saidturntable, a shaft driven by said motor at a predetermined speed havinga driving member on the end thereof, a spindle connected with saidturntable having a driven member mounted thereon, and manually operatedmeans for locking the driven member and shaft to be directly driven bysaid driving member when said means is moved to one position andunlocking the same for permitting said member to be indirectly driven ata diiferent speed when said means is moved to another position.

17. In combination, a spindle operable at a constant speed, a speedchange mechanism mounted on said spindle as a unit and including aclutch, means carried by said spindle for driving the mechanistic! saidunit, a record support rotatably mounted on said spindle and adapted tobe driven by said unit, and manually operable means for controllingsaidclutch whereby said recordsupport is driven by said unit at one orthe other of two difierent speeds.

18. In a phonograph, the combination of a motor driven spindle operableat a constant speed, a turntable loosely mounted on said spindle, a twospeed driving m mounted on said spindle as a unit and including aclutch, drive means coupling said mech to said spindle, means carried bysaid mec adapted to engage and drive said turntable, manually operablemeans for controlling said clutch at will to selectively couple saidmechanism directly and indirectly to said spindle, and means controlledby said manually. operable means for preventing movement of said unitwhen said mechanism is coupled indirectly to said spindle.

v la. con.

